从列表中分配变量，或“如何制作优雅的保存功能”

Question

I'm currently working on a small text based game, the game remembers the gamestate based on global variables, for example, goblins_dead to see if you've killed the goblins yet.

This worked pretty well, until I decided to add a save and load function. The save function works, the load function does not, and while I know why, I can't come up with an easy fix.

The way the save function currently works is this, I have a list with all the global variables we've used in the game so far. Then I have the list run through each varaiable and give a 1 if its true or a 0 if its not, at the end it prints a "seed" that consists of a list of 1s and 0s the user can input. It looks like this, in my sample test code

def game_save():
    print "This will give you a seed. Write it down, or see seed.txt"
    print "When you start a new game, you will be propted to give your seed. Do so to reload."
    global goblins_defeated 
    global lucky
    global princesshelp

    end = "done"
    load_seed =[goblins_defeated, lucky, princesshelp, end]
    load_seed.reverse()
    variable = load_seed.pop()
    seed = []
    print globals()

    while end in load_seed:
        if variable == True:
            seed.append("1")
            print "APPENEDED 1"
            print load_seed
            variable = load_seed.pop()
        elif variable == False:
            seed.append("0")
            print "APPENED 0"
            print load_seed
            variable = load_seed.pop()
        else:
            print "ERROR"
            break

    seedstring = ' '.join(seed)

    print "This is your seed %s" %seedstring

This code works, it yields a string, that matches the values in the way I want.

The issue comes when its time to load. I inverted this process, like this:

def game_load():
print "Please type your seed in here:"
global goblins_defeated 
global lucky
global princesshelp
end = "done"

seedlist = [goblins_defeated, lucky, princesshelp, end]

seed = raw_input("> ")
seed_list = seed.split(" ")
seed_value = seed_list.pop()
variable_list = [end, goblins_defeated, lucky, princesshelp]
variable = variable_list.pop()
testlist = []

while end in variable_list:
    if seed_value == '1':
        variable = True
        print variable_list
        print variable
        print seed_value
    elif seed_value == '0':
        variable = False
        print variable_list
        print variable
        print seed_value
    else:
        print "ERROR ERROR FALSE LOOP RESULT"
        break

    if bool(seed_list) == False:
        print "List is empty"
    else:
        seed_value = seed_list.pop()

    variable = variable_list.pop()

The mistake will be obvious to more seasoned programmers, it turns out lists load what a variable points at, not the variable name, so I can't assign things in this way.

This is where I'm stumped, I could just make a long list of if statements, but that's not very elegant. Further reading suggests that a dictionary approach might be the way to solve this, but I'm unsure on how I would go about implementing a dictionary, more specifically, I'm not sure how dictionaries interact with variables, my understanding is that this is how variables are actually stored in python, but I'm not sure how to get started on accessing and storing those variables reliably, or if I could use a global dictionary to store all my variables in the game properly. Basically, I'm unsure of how to "correctly" use a dictionary to its full potential, specifically how it interacts with variables.

Answer 1

That's much larger than necessary. Just use string formatting to provide the save password:

print 'Your seed is {}{}{}{}'.format(goblins_defeated+0, lucky+0, princesshelp+0, end+0)

Adding 0 converts each boolean into its numeric representation. Each value is inserted into the string, replacing the {} .

Load like this:

seed = raw_input("> ")
goblins_defeated, lucky, princesshelp, end = map(bool, map(int, seed.split()))

This splits seed on whitespace, maps each element to an integer, then maps each of those integers to a boolean, then unpacks that map object into the appropriate variables.

You don't necessarily have to store these conditions as booleans at all, as 1 and 0 will evaluate similarly, with 0 for False and 1 for True . Booleans are actually a subclass of int anyway. You can even do math with them, eg True+True equals 2 .